The Cascade of the melody helped the child to fall into a peaceful slumber.
I would go with B, or Ways to build immunity to diseases. Why? Well, just by using the word biology, we can use process of elimination. The prefix “bio” means life, so C and D already would be out. The suffix “ology” means the study of, so the word biology means the study of life. Because biology often has to do with diseases and finding cures to sustain human life spans, the only logical answer would be B. A would make no sense in terms of biology.
Reference: the action of alluding or mentioning something; source; things that you have used for an assignment
